Sealing apparatus for cathoderay tubes



Oct. 30, 1951 w. P. MELCHER ETAL 2,

SEALING APPARATUS FOR CATHODE-RAY TUBES Filed Nov. 50, 1950 2 SHEETS-SHEET 1 x A. F /g.l

4o 2| I I 42 42 I Q 22 I 22 Q s s eAs+ I 2o/// n ELEVATING 2 I 9 45 SHOE 21 34 32 32 ROLLER I 4 33 33 I 35 I AAA '9 AH HINGE y ROTARY AIR SEAL 29 llWE/VTOHS WALTER P MELCHER HARRY H. VOELZ THE/f? ATTORNEY Oct. 30, 1951 w. P. MELCHER ETAL I 2,573,266

SEALING APPARATUS FOR CATHODE-RAY TUBES Filed Nov. 50, 1950 2 SHEETSSHEET 2 ELEVATING SHOE ELEVATING INVENTORS WALTER F. MELCHER HARRY H. VOELZ THE /R A TTOR/VEY Patented Oct. 30, 1951 SEALINGeA'PPARATUS 'FOR ;GATHODE-l- Y RAY Tones Walter P, Meleherrand Harry Yoelz Chicago,

' corporation of Illinois 11 a sighors t f fh a anqi-e rnprati a'a App ication Na emher 3o, inte ral othan I invention relates to improved apparatus ferti e fabrica i o ath e-ray tube o the type having an envelope comprising a neck per..- tion of vitreous material such as glass ,or the like, a hollow flared or generally .coni'cal portion, and a window or viewing plate of glass or similar transparent material. More particularly, this invention is directed to improved apparatus {for sealing-the glass viewing plate to the ,con-ical portion of a cathode-ray tube in whichthese portions have a rectangular or other 'nonecircular cross section.

In many cathode-ray tubes the conical portion 'of the envelope is composed of metal and 'is lus ually provided with a flange or lip at one end in which the glass window or face plate-is fitted. tor sealing purposes. To obtain a satisfactory seal, it is preferable that the metallic cone be held with its axis in a vertical position and the window be placed on its upper end in contact withthe flange. Gas burners may then be directed to the under portion of the flange and the assembly rotated about its axis for uniformity of heating. The heat from the burners causes the glass ofthe Window to soften and settle in the flange, sealing the window to the metallic portion.

Heretofore in the art it has been usual that cathode-ray tube envelopes be composed of a tubular neck portion, a hollow conical portion of circular section and a circular face plate. As previously stated, the face plate may be sealed to the conical portion by placing the cone in .a suitable apparatus with its large end upward and the face plate resting thereon. An array of sealing elements may be positioned to surround the conical portion and directed to its upper end. Relative rotation may then be imparted between the burners and the conical portion for uniform heating. The advent of rectangular-screen cathode-ray tubes for use in television receivers has presented a serious sealing problem. That is, it has become necessary to provideapparatus bymeans of which heat may be applied uniformly to the'sealing sllliace between the cone and face plate portions of a cathode-ray tube envelope when the sections of these portions are not circular. ,As lon as these sections are circular, uniform heat.- ing may be obtained simply by arranging the sealing elements in an array surrounding the cone and effecting relative rotation between the cone and the sealing elements, as described above.

The present invention provides improved apparatus e ecting an efficient seal between the 5 (i a' msyiewingeplateportion and hollow envelope portion of a cathode-ray tube when these portions ,havea non-circular section, and renders feasi-ble the production of rec tangularescreen cathoderay tubes especially of the metallic type. The apparatus comprises a supporting table witha structure mounted on the table for supporting the hollow envelope portion which may beer generally conical shape with a flange formed at its lar e nd Th ne issupmrt d in th aforementioned structure with its flanged end upwa d and with e vi ing .p e'resting there ,on. An array ,of heating elements is movably supported by the table around the coneand di rected to the flanged end. A cam member havin a confi urat o corresponding tothat o the flanged end is mounted ,onthe supporting structure in coaxial relation with the cone, and the cone is supported so that the plane of thefianged end is parallel to the plane of the cam. Resih ient means are provided for biasing the heating elements into engagementwith the cam to con} or t patternlor t arra t h pe ip a configuration .of the flanged end. Finally, the apparatus includes a driving means for impart ing relative rotational motion between the cam and t a ra of h ating-e m nt It is, accordingly, an objectof this invention to provide improved apparatus for sealing the viewing-plate of a cathode-ray tube to a hollow envelope portion of the tube.

A more partieular object of the invention is to provide r pr ve ap ra usior s ling th vi ing plateof a cathode ray tube to theflanged end eta ho low me alhc env lop o t o h flanged end having a rectan ular orlothe r non-circular in which:

Figur 1 sh w ne mhadi proved sealing apparatushf t e invention,

F e 2 shows a v o t e app a us-o E hre tak n a ong th nes .2 o Figure 1, and

Eigure3 shows a viewof the window or view-- ing plate of the cathodeeray tube taken along the i -3 of ig re .1-

ilhe apee e aei F -te .1 nclude a s ppo t ing meansortable l' hayin a upwardly-en: tee Ill- 9%?- 41 r atahlr m; of the means for the conical portion 2| of a cathode- Cone 2| rests in bracket 20 1 ray tube envelope. and is held in place by means of brackets 22, so that rotation of the turn table causes rotation of the cone. Brackets l9 additionally support a cam member 23 having a peripheral configuration corresponding to the configuration of the.

flanged end 24 of cone 2|. Cone 2| is supported in coaxial relation with cam 23 and with the plane of its flanged end 24 parallel to the plane of the cam.

The apparatus also includes an air tube 25 mounted coaxially within tubular driving member H in frictional engagement therewith and extending upwardy through turn-table I8 and into the neck portion 26 of the cathode-ray tube envelope, the neck portion having been scaled to the lower extremity of metallic portion 2| in a previous sealing operation. Air tube 25 extends into neck portion 25 through a rubber air seal 27 and has a small aperture 28 formed therein which acts as a bleeder. Air is introduced into the air tube through a rotary air seal 29 of well-known construction. -A plurality of upwardly extending rods 30 are movably mounted on supporting table ill by means of pivot members 3|. Only two such rods are shown in the drawing for purposes of simplicity, but it is to be understood that a number of these rods are mounted on supporting table I surrounding cone 2|. Rods 30 each have a roller 32 supported thereby for engagement with the periphery of cam 23, the axial position of the roller being adjustable on each rod by means of a sliding collar 33 and adjusting screw 34. The rods 30 are biased inwardly by means of flat springs 35 to bring rollers 32 into engagement with the cam periphery. Should it be found that insuificient tension is obtained by the flat spring a coil spring may be mounted on the rods to encircle them and urge rollers 32 into firm en: gagement with the periphery of cam 23. 7 Each of the rods 3|] supports a cylinder and piston assembly 36, the cylinder portion of the assembly being secured to the rod by means of a slidable collar 31 and adjusting screw 38. The piston portion of the assembly is spring-urged downwardly so that a roller 39, mounted at the lower end of the piston, engages the upper surface of cam 23'. The upper end of the piston supports a burner 40 which is secured thereto by means of an L-shaped bracket 4|. The burner is mounted on a pivot 42 which frictionally holds the burner in any desired radial osition. Bracket H is slotted to allow lateral adjustment of the position of the burner.

To perform the sealing operation, cone 2| and neck portion 2B of the cathode-ray tube are placed in bracket 20, as shown, and a viewing plate 43 is placed on flanged end 24 of the cone. Rubber air seal 21 is then inserted into the neck portion, as shown. Electric motor is energized to rotate turn table l8 and, therefore, the oathode-ray tube assemblys Burners 40 are ignited 4 and directed to the underside of flanged end 24 of the cone. Rotation of the turn table causes cam 23 to rotate which, in turn, causes the burners to follow the contour of the flanged end. Air is introduced through air tube 25 into the interior of the tube to prevent the edge of viewing plate43 from sagging during the sealing operation. The aperture 28 in the air tube allows some of this air to escape and avoids excessive pressure in the interior of the cathode-ray tube envelope.

.-It is sometimes desirable that viewing plate 43 be heated prior to the sealing process to prevent cracking. This may be accomplished by the provision of a burner 5|! adjustably supported by a rod 5| for directing a soft flame to the top of the viewing plate.

Insome instances flanged end 24 of the cone may have an irregular elevational configuration,

for example, it may be curved upwardly as shown at 44. Accordingly, it is desirable thatburners 40 may also be elevated so that they may follow curve 44 and provide uniform heating of the flanged end. This is accomplished by the provision of elevating shoes, such as 45, on the surface of cam 23. These shoes have a curvature corresponding to curvature 44 of the flanged end and the rollers 39 ride along the elevating shoe and thus enable the burners 40 to follow the curvature. 1

Figure 2 shows one configuration of cam- 23 which may be used when it is desired to seal a rectangular face plate to a generally conical envelope portion of rectangular section. The cam has a pair of elevating shoes 45 mounted thereon to perform the afore-described elevating function. The plurality of rollers 32 engage the peripheral surface of cam 23 and are mounted on a corresponding plurality of upwardly extending rods 30, as shown in Figure 1. I

Figure 3 represents a top view of the rectangular cathode-ray tube envelope with the viewing plate 43 mounted on flanged end 24 of the conical portion.

This invention provides, therefore, improved apparatus for sealing the viewing plate of a cathode-ray tube envelope to a hollow envelope portion of generally conical configuration having a flanged end with a given configuration. Itis apparent that the apparatus may be used to perform its sealing function on envelopes having anygiven cross sectional configuration, it being merely necessary that cam 23 have a corresponding configuration. Regardless of the configura tion of the flanged end of metallic portion 2|, the burners are caused to follow its contour and provide uniform heating around its periphery so that a satisfactory seal may be obtained. More over, when so desired, the apparatus is readily adaptable for sealing the viewing plate to the conical portion of a cathode-ray tube envelope of well-known circular section, it being merely necessary to provide cam 23 with a correspond-. ing circular section.

While a particular embodiment of the invention has been shown and described, modifications may be made, and it is intended in the appended claims to cover all such modifications as may fall within the true spirit and scope of the invention.

We claim: g

1. Apparatus for sealing the viewing plate of a cathode-ray tube to a hollow envelope portion having a flanged end of a given configuration '75 comprising: a structure for supporting 'said' en-' velope portion with its flanged end upward to receive said viewing plate; an array of heating elements movably supported by said structure around said envelope portion and directed toward said flanged end; a cam positioned within said array and having a configuration corresponding to that of said flanged end; means for biasing said heating elements into engagement with said cam to conform the pattern of said array to the configuration of said flanged end; and means for effecting relative rotation between said array of heating elements and said cam.

2. Apparatus for sealing the viewing plate of a cathode-ray tube to a hollow envelope portion having a flanged end of a given configuration comprising: a supporting means; a structure rotatably mounted on said supporting means for supporting said envelope portion with its flanged end upward to receive said viewing plate; a driving mechanism coupled to said structure for imparting rotational motion thereto; an array of heating elements pivotally mounted on said supporting means around said envelope portion and directed toward said flanged end; a cam positioned on said structure within said array and having a configuration corresponding to that of said flanged end; and means for biasing said heating elements into engagement with said cam to conform the pattern of said array to the configuration of said flanged end.

3. Apparatus for sealing the viewing plate of a cathode-ray tube to a hollow envelope portion having a flanged end of a given configuration comprising: a supporting means; a structure rotatably mounted on said supporting means for supporting said envelope portion with its flanged end upward to receive said viewing plate; a driving mechanism coupled to said structure for imparting rotational motion thereto; an array of heating elements pivotally mounted on said supporting means around said envelope portion and directed toward said flanged end; a cam positioned on said structure within said array in coaxial relation with said envelope portion in a plane parallel to the plane of said flanged end, and having a configuration corresponding to that of said flanged end; and means for biasing said heating elements into engagement with said cam to conform the pattern of said array to the configuration of said flanged end.

4. Apparatus for sealing the viewing plate of a cathode-ray tube to a hollow envelope portion having a flanged end of a given configuration comprising: a supporting means; a structure rotatably mounted on said supporting means for supporting said envelope portion with its flanged end upward to receive said viewing plate; a driving mechanism coupled to said structure for imparting rotational motion thereto; an array of support rods pivotally mounted on said supporting means around said envelope portion; a cam positioned on said structure within said array in coaxial relation with said envelope portion in a plane parallel to the plane of said flanged end, and having a configuration corresponding to that of said flanged end; a corresponding array of cam-engaging members respectively supported by said rods; resilient means for biasing said rods to bring said cam-engaging members into engagement with said cam; and a plurality of heating elements respectively supported by said rods and directed toward said flanged end.

5. Apparatus for sealing the viewing plate of a cathode-ray tube to a hollow envelope portion having a flanged end of a given configuration comprising: a supporting table; an upwardlyextending tubular member rotatably mounted on said table; a structure afflxed to said tubular member for supporting said envelope portion with its flanged end upward to receive said viewing plate; a driving mechanism coupled to said tubular member for imparting rotational motion thereto; an array of upwardly-extending support rods pivotally mounted on said table around said envelope portion; a cam positioned on said structure within said array in coaxial relation with said envelope portion in a plane parallel to the plane of said flanged end, and having a configuration corresponding to that of said flanged end; a corresponding array of roller members respectively supported by said rods; resilient means for biasing said rods inwardly to bring said roller members into engagement with said cam; and a plurality of heating elements respectively supported by said rods and directed toward said flanged end.

6. Apparatus for sealing the viewing plate of a cathode-ray tube to a hollow envelope portion having a flanged end of a given sectional configuration and ofa given elevational configuration, said apparatus comprising: a supporting table; an upwardly-extending tubular member rotatably mounted on said table; a structure aflixed to said tubular member for supporting said envelope portion with its flanged end upward to receive said viewing plate; a driving mechanism coupled to said tubular member for imparting rotational motion thereto; an array of upwardly-extending support rods pivotally mounted on said table around said envelope portion; a cam positioned on said structure within said array in coaxial relation with said envelope portion in a plane parallel to the plane of said flanged end, said cam having a peripheral configuration corresponding to the sectional configuration of said flanged end and an elevational configuration corresponding to the elevational configuration of said flanged end; a corresponding array of roller members respectively supported by said rods; resilient means for biasing said rods inwardly to bring said roller members into engagement with the periphery of said cam; a plurality of heating elements reciprocally supported by said rods and directed toward said flanged end; and resilient means for urging said heating elements downwardly against the top surface of said cam.

WALTER P. MELCHER. HARRY H. VOELZ.

No references cited. 

